Paint spraying system



April 18, 1961 J. KOZINSKI PAINT SPRAYING SYSTEM Original Filed March 4,1954 OBJECT 7'0 55 PAINTED INVENTOR. Jwwfi (az/rmf ATmQA/EV PAINTSPRAYING SYSTEM Joseph Kozinski, Chicago, 111., assignor to H. G.Fischer 8: Co., Franklin Park, 111., a corporation of Illinois 2 Claims.(Cl. 239-15) This invention relates to a paint spraying system, andparticularly of the type involving the use of high potentialelectrostatic fields for directing particles of paint toward the objectto be painted. Electrostatic field paint spraying systems depend uponthe fact that paint to be applied to an object is finely divided andthendisposed in an electrostatic field. The electrostatic field eitherterminates at or passes through the article to be painted. The paintparticles as electrified fine particles move along lines of potentialgradients.

The efiiciency of an electrostatic paint system depends, among otherthings, on the fineness of the paint particles and the velocity attainedby the paint particles just prior to their impact upon the article to bepainted.

While a variety of means for obtaining paint in finely divided form anddisposing the same in an electrostatic field are known, such means arerelatively complicated or inefiicient. The quick-drying characteristicsof paint or lacquer or whatever material is used, together with the highpotential insulation requirements, render this problem diflicult ofsolution; Furthermore, the requirement that a paint spraying system besimple, safe and foolproof and also be free from service trouble,imposes additional requirements. v

In accordance with this invention, a simple system is provided wherebythe material to beapplied, such as paint, lacquer, varnish or the like,is first atomized in a simple and effective manner and is disposed in anelectric field so that the finely atomized particles may move in theproper direction toward the article to be covered.

In order that the invention may be understood, an exemplary embodimentwill now be disclosed in connection with the drawings.

Referring to the drawings:

Figure l is a partly diagrammatic view of a paint spraying systemembodying the present invention.

Figure 2 is an elevation of the atomizing means.

Figure 3 is a sectional detail on line 3-3 of Figure 2.

The paint or lacquer or whatever material is being applied may be storedin paint tank of any desired construction. Tank 10 may be as large asnecessary and may be of metal or an insulating material and may have acover or not, as desired. Tank 10 has outlet 11 from the bottom thereofto which is attached pipe 12. Pipe 12 is preferably of insulatingmaterial and may be of flexible hose of rubber or of plastic materialhaving the desired chemical characteristics and having good electricalinsulating qualities. A valve is provided for controlling the flow ofliquid from tank 10 into pipe 12.

Pipe 12 has end 13 which is provided with a suitable slip joint engaginghollow shaft 14 of motor 15. Motor 15 may be of any desired constructionand because of the possibility of explosion, may be of the enclosedtype.

Motor 15 is different from a conventional motor only in having a hollowshaft 14 rather than a conventional solid shaft. Motor 15 may besupported in any suitable manner provided, however, that the entiremotor is inpaint particles pass through electrode 40.

2,980,33? Patented Apr. 18, 1961 sulated from ground for the fullpotential used in the electrostatic system.

Motor 15 supports concave electrode 17, the electrode being stationaryand being rigidly supported from the motor casing in any suitablefashion. Electrode 17 may have any desired .shape and as illustratedhere, has the general shape of a hollow bowl. The electrode may consisteither of metal, such as copper, aluminum or iron, or may consist of anyinsulating material having a metal film of copper, aluminum, iron or anyother material desired. Electrode 17 has centrally disposed aperture 18(Figure 3) through which hollow motor shaft 14 passes. The end of motorshaft 14 has rigidly attached thereto spinner 20 for atomizing liquid.

Spinner 26 has tubular attaching portion 21 for engaging motor shaft 14.Attaching portion 21 forms part of spider 22 extending outwardly of thespinner and terminating in annular fiat ring 24. Ring 24 has a number ofradially disposed blades or vanes 25. Spider 22 also carries fixture 27defining chamber 28 for capping the open end of motor shaft pipe 14.Fixture 27 may assume a variety of forms and, as shown here, consists ofcircular disc 29 and flat annulus 30 joined together by rim 31. Rim 31has a number of apertures therethrough for connecting chamber 28 withinthe fixture to thecxterior of the fixture. 33 rigidly attached to rim 31so that in effect the fixture has a number of radially directed tubes.Preferably, these tubes are so arranged as illustrated in Figure 2 sothat the tubes are along radii which extend between adjacent vanes, thetubes themselves terminating short of the inside edges of the vanes. Thefixtures and tubes are disposed so as to lie within thespread of thevaries as illustrated in Figures 1 and'3. I

The spinner will be rotated at high speed by motor 15, paint beingsuppliedto chamber 28 through the hollow shaft of the motor. .Motor 15is energized by secondary 36 of transformer 37. Transformer 37 hasprimary 38 for connection to a conventional power circuit such as, forexample, .a 110 volt. 60 cycle line. 1 Transformer 37 has secondary, 36insulatedfor high potential from primary 38 and from the iron core.Secondary 36 is connected by suitable leads 40 to the winding of motor15.

As will be readily understood, electrode 17 must be at a high directpotential with reference to ground for proper operation of the paintspraying system. In accordance with this invention, electrode 17, motor15 and secondary 36 of the transformer will all be at high potential andwill be adequately insulated from ground and also will be so designed orprotected as to prevent an operator from contacting the same while thepotential is being applied.

The dotted lines indicate the parts of the system at high potential.Inasmuch as paint supply tube 12, or at least part of it, will be ofinsulating material, hollow shaft 14 of the motor will be electricallyinsulated from the parts of the paint supply which might normally haveto be handled, and no special means for insulating the paint tank and atleast part of the piping will be required.

The object to be painted, .generally indicated by 49, may be any desiredarticle. As a rule,.the article to be painted may be of metal or have ametal film thereon so that it functions as an electrode and may be at asuitable potential with respect to electrode 17. However, in certaininstances, electrode 40 cooperating with electrode 17 may be disposed inback, that is, to the left of the article to be painted, so that thearticle is in the direct line of travel between electrode 17 and thecooperating electrode. In other instances, electrode 40 may be a metalscreen or grille in front of the work so that th At these apertures arestub tubes.

If t c 7 3 ,7 lbo -polarity of electrodes-40 and electrode 17 vary-dep'ending uponthetype ofisystem and the material eused for painting orcovering, Thus in certain cases, electrode 1 7 may have to be negativeto electrode 40 and in I OTher instaiiCeSE-th 'PoIafit-y niust bereversed'." -'I= his is a simple matter and, as a rule, consists in'merely i'eversiing sioii leads-of manipulating-a; switchiina able in theAs a rule,'fa"power supply; for ,a

system' of thischaracter. must generate or provide potentials ioftlie-order'of lgfl0oyolts or -niore,'-the current V interlocks may heprovided 'toprevent: an operatorffforn toucliing-or themotofior electfode lq A's-a-i'u1e, the object-to bepainted, if of metal,

or electrode 40 cooperating therewith, will beat ground potential whileelectrode" 17 will be either atl e high'pdsitive or negative potentialwith respect to ground. Ihe revolution of thespinner will provide apumpingaction independently of the ;tendency of paint to flow fimthe-fank-to the spinner. In factLthe tank for paint,

need not. necessarily be locatedeabove the spinner, and inmanyginstances,the-tank may be located below the level of thefspinnerthe supply pipe' 12 extending downwardly into the -tank-from the' bottomthereofi Thehigh:

speed -of the spinner} will serve to-throw out theliquid paint d;vaisnish orwhatever is being used, the blades striking the liquid andato'mizing the same to fine' partie le s 'fl lfhef atomized particleshave already acquirdieleetricecharges due to the high-potential of motorshaft ld,-

which will be of, steel," and the various 'spinner parts, I

piefei ably-bf metal." :Electrode 17,.is provided' principa1ly to shape=of eleptrical force going to electrode 40.1,

Thus ele'ctiodefllneed be shaped only to have a desired effect {on theshape of-the electric-field: The atomizing motor may be, conventionaleven though at high potential. .1,

' lnsfeadflof the atomizingnieausilluStreitedgother atomizing' means maybe us'ed in 'connectiom-with the motor.

'i applicatipnis a division of my application Serial: No. 414,00 9, filed March-451954. L

what isclailned isz Fo'r use m an electrostatic type paint spray system,

the combination of. an alternating I current electric motor supply toiobtaining adesiredihighpotentialg is iiof showij, sueli supplies beingwell known and availhaving a stator and rotor including e hollow metalshaft,

'ea -hollowlrotary coupling and stationary pipe providing a-connectingmeans between one end of said hollow shaft and a stationary paint tank,saicl connecting means including high potential insulation along theline of paint travel betweensaid shaft end and said paint tank,atomizing means carried byfthefbthbr end of said hollow shaft forreceivi ai t datqae z eeth e me during motor rotation; at'ransformer'having primary and secwindia a esqaae t oa be ween 3i15c1IY and; said. electin motor iqrippe atiugi heis me r m s i t pq P aY.,LW a i aP as r z dfiimm e nfi aa iets zia aisl esnfl 1 providing a'suitable potential for operating a'motor, and high potential insulation;between,,saidprimary alid 'se'condary windings,"nieansforsupportingsaidelectric motor as a whole to provide high potential insulation, saidatomizing means being adapted to be at high potential during "sprayingwhereby thei complete atornizi'ng system including .ithefrnoto'r may be;at high potential relative to ground withou t communicating such highpotential to the,

paint supply or to the power'line, said electric motor being oigenerally conventional construction and Hacking sufficient insulation-betwe enl its windings and name to withstaud-thehighlpotentiali 1 1 1---2. The combination according-to claim "1' wherein a stationarymetal-bowl is supported by" said stator', .said metal bowl facing awayfrom-the motor with-the motor shaft passin'g through the-san1eandtheatomizifig means iae asfi t ia e ei fie a il a w s 1 Y liefelencesQited in the'fileof thisipatent ffi i PAT N S' Nov i 17,1 11931 1211.12,;-1940 '2,6 98 ,'8l4* -Ransbur 1;- g 1211154 1955

